In the communications industry, much attention has been focused on making more effective use of the limited number of transmission channels available for delivering video information and programming to an end user. Various methodologies have been developed to achieve an increase in the number of available transmission channels within the frequency bandwidth that was previously allocated to a single video transmission channel. An increase on the number of available transmission channels would allow the communications industry to reduce costs and to increase broadcast capacity. It has been estimated that a typical cable operator could have the capability to deliver as many as 500 channels to a home viewer.
A dramatic increase in the number of separate program channels that could be broadcast within the currently available transmission bandwidth may be realized by employing a process of compressing and decompressing video signals. Typically, the video and audio signals comprising a video program are converted into a digital format, compressed and encoded in accordance with an established compression algorithm or methodology. The compressed system signal or bitstream, which is understood to include a video portion, an audio portion, and other informational portions, may then be transmitted over existing television channels, cable television channels, satellite communication channels, and the like. A decoder is then typically employed to decompress and decode the received system signal in accordance with the same compression algorithm or methodology previously mentioned. The decoded video information may then be output to a display device, such as a television monitor.